Simultaneous process optimization and heat integration based on rigorous process simulations

This paper introduces a simultaneous process optimization and heat integration approach, which can be used directly with the rigorous models in process simulators. In this approach, the overall process is optimized utilizing external derivative-free optimizers, which interact directly with the process simulation. The heat integration subproblem is formulated as an LP model and solved simultaneously during optimization of the flowsheet to update the minimum utility and heat exchanger area targets. A piecewise linear approximation for the composite curve is applied to obtain more accurate heat integration results. This paper describes the application of this simultaneous approach for three cases: a recycle process, a separation process and a power plant with carbon capture. Case study results indicate that this simultaneous approach is relatively easy to implement and achieves higher profit and lower operating cost and, in the case of the power plant example, higher net efficiency than the sequential approach.     

On Asymptotic Theory for ARCH (∞) Models

Autoregressive conditional heteroskedasticity (ARCH)() models nest a wide range of ARCH and generalized ARCH models including models with long memory in volatility. Existing work assumes the existence of second moments. However, the fractionally integrated generalized ARCH model, one version of a long memory in volatility model, does not have finite second moments and rarely satisfies the moment conditions of the existing literature. This article weakens the moment assumptions of a general ARCH( ) class of models and develops the theory for consistency and asymptotic normality of the quasi‐maximum likelihood estimator.     

An analytical model for real gas flow in shale nanopores with non‐circular cross‐section

An analytical model for gas transport in shale media is proposed on the basis of the linear superposition of convective flow and Knudsen diffusion, which is free of tangential momentum accommodation coefficient. The present model takes into the effect of pore shape and real gas, and is successfully validated against experimental data and Lattice–Boltzmann simulation results. Gas flow in noncircular nanopores can be accounted by a dimensionless geometry correction factor. In continuum‐flow regime, pore shape has a relatively minor impact on gas transport capacity; the effect of pore shape on gas transport capacity enhances significantly with increasing rarefaction. Additionally, gas transport capacity is strongly dependent of average pore size and streamline tortuosity. We also show that the present model without using weighted factor can describe the variable contribution of convective flow and Knudsen diffusion to the total flow. As pressure and pore radius decrease, the number of molecule‐wall collisions gradually predominates over the number of intermolecule collisions, and thus Knudsen diffusion contributes more to the total flow. The parameters in the present model can be determined from independent laboratory experiments. We have the confidence that the present model can provide some theoretical support in numerical simulation of shale gas production. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2893–2901, 2016     

利用赤泥制备轻质高强保温装饰一体化建筑材料

利用赤泥为主要原料,添加建筑垃圾、抛光砖废料和粘土制备轻质高强保温装饰一体化建筑材料.通过改变赤泥用量、烧结温度、发泡剂添加量等条件,对样品体积密度、孔隙率、抗压强度进行了研究.利用X射线衍射仪(XRD)、扫描电镜(SEM)对样品物相组成和形貌进行表征.研究结果表明:赤泥用量为35%,发泡剂添加量为5%,烧结温度为1100℃时,制备样品的气孔分布均匀,孔径大小较一致,体积密度为0.26 g/cm3,孔隙率为73.28%,闭气孔率达到90.52%,抗压强度为7.83 MPa.     

Analysis and Practice of ＂2.5 ＋ 0.5＂ Talent Training Mode of Vocational Chemical Fiber Profession

实施校企结合＂2.5＋0.5＂人才培养模式,学生在前5个学期完成教学计划所规定的各项教学环节,包括毕业设计及毕业答辩,第六学期在校外实训基地进行顶岗实习;培养热爱化纤专业并具有较强纺丝工艺分析、设备维护、产品性能检测的高素质技能型人才。     

一个化工过程运行系统的多层信息集成平台

In the process industry, automation and process control systems are widely implemented, information integration is however far away from satisfactory. It remains a hard job for senior managers to make decisions based on the plant-wide real-time integrated information. This paper proposes a multi-layer information integration platform. In the data integration level, the standard for the exchange of product (STEP) and the extensible markup language (XML) are used to unify these data of the chemical process. In the model integration level, the models are integrated by using the neutral model repository and CAPE-OPEN. In the integration of process task, the common object request broker architecture (CORBA) is used as the communication mediator. The XML is taken as the data standard. A uniform information platform is thus constructed and realized. The proposed information integration platform is satisfactorily implemented to solve the Tennessee Eastman (TE) problem.     

A Multi-layer Information Integration Platform for Chemical Process Operation Systems

In the process industry, automation and process control systems are widely implemented, information integration is however far away from satisfactory. It remains a hard job for senior managers to make decisions based on the plant-wide real-time integrated information. This paper proposes a multi-layer information integration platform. In the data integration level, the standard for the exchange of product (STEP) and the extensible markup language (XML) are used to unify these data of the chemical process. In the model integration level, the models are integrated by using the neutral model repository and CAPE-OPEN. In the integration of process task, the common object request broker architecture (CORBA) is used as the communication mediator. The XML is taken as the data standard. A uniform information platform is thus constructed and realized. The proposed information integration platform is satisfactorily implemented to solve the Tennessee Eastman (TE) problem.     

第三方涂装管理浅谈

第三方涂装是指制造加工行业或其零部件的制造商将其所有的涂装生产全部外包给第三方——专业的涂装工程企业。本文介绍了制造加工企业如何进行第三方涂装管理。     

工科化学专业毕业实习改革模式初探

在市场经济转型的环境中,高校办学面临扩招以及经费不足造成的压力,致使工科化学专业毕业实习难以正常进行,因此对毕业实习模式进行改革势在必行。我院探索了仿真实训、毕业实习与就业一体化以及毕业实习与毕业设计一体化三种新的模式。经过实践证明,这三种模式均有效地提高了人才培养质。